Amyotrophic lateral sclerosis (ALS) is a devastating, degenerative neurological disease with relentless progression. The average life span from onset of symptoms to death is three years. No treatment has been found to improve muscle strength. Riluzole, the only drug approved by the FDA for treatment of this disease, has been shown to prolong life by about three months. Although free radical damage is believed to play a key role in the pathogenesis of ALS, antioxidant substances that scavenge free radicals have not been shown to help patients with ALS. The use of a ketogenic diet would theoretically reduce free radical production, thus decreasing free radical damage, by decreasing oxidation of citric acid cycle intermediates and may be useful in the treatment of ALS.